How to fix flicker when using Webkit transforms & transitions
Try using translate3d instead of translateX. It appears only translate3d is hardware accelerated on iPad 3.2.
@gargantaun is right, Webkit flickers if the element you want to animate is bigger than the screen. But there is an easy fix. Just add:
-webkit-backface-visibility: hidden;
to the element and you are good to go!